LECTIN HISTOCHEMISTRY OF HUMAN LEUKEMIC MAST-CELLS (HMC-1) TRANSPLANTED INTO SEVERE COMBINED IMMUNODEFICIENT (SCID) MICE

It is difficult to isolate and impossible to propagate human mast cell s in tissue culture. As an alternative to the use of human differentia ted mast cells, a human leukaemic mast cell line (HMC-1), which can be propagated in vitro, has been employed in a number of studies. Carboh ydrate binding proteins, lectins, have been used to characterise the t erminal sugar residues of human mast cells in situ. The aim of the pre sent study is to characterise the lectin binding sites of HMC-1 cells transplanted into severe combined immunodeficient (scid) mice. Lectins specific for the complex carbohydrates, neuraminic acid and N-acetylg lucosamine residues showed generally a strong uniform binding pattern, whereas mannose and glucose specific yielded lectins a greater hetero geneity. This glycotope expression pattern has some similarities with those of human mast cells in situ, and therefore HMC-1 cells grown in scid mice constitute a valuable model system for the study of carbohyd rate expression in human mast cells.